scholarly journals Observations of Habitat Use by Polar Bears, Ursus maritimus, in the Alaskan Beaufort, Chukchi, and Northern Bering Seas

2004 ◽  
Vol 118 (3) ◽  
pp. 395 ◽  
Author(s):  
Donald J. Hansen
Keyword(s):  
Habitat Use ◽  
Polar Bear ◽  
Beaufort Sea ◽  
Ice Cover ◽  
Ursus Maritimus ◽  
Bowhead Whale ◽  
Polar Bears ◽  
Management Service ◽  
Aerial Surveys ◽  
Sea Coast

A total of 1112 Polar Bears (Ursus maritimus) at 482 sightings were recorded during aerial surveys in the Beaufort, Chukchi, and northern Bering Seas conducted primarily during September and October from 1979-1999. Of these bears, 784 were observed offshore at 400 sightings. The surveys were conducted by the Naval Ocean Systems Center and Minerals Management Service; they were designed to monitor the fall Bowhead Whale (Balaena mysticetus) migration. Over the 20-year period, 1,096,620 kilometers of surveys were flown. The majority of the offshore Polar Bears, 595 bears at 290 sightings, and most of the kill sites and polar bear tracks were recorded in 80-100% ice cover. The number of bears per kilometer increased substantially in >24% ice cover, with the highest number observed in 80-100% ice cover. This habitat use probably is related to the availability of seals, their primary prey. There were 328 bears (83 sightings) recorded on land, and most of them were associated with whale carcasses and bowhead whale subsistence harvest sites along the Alaskan Beaufort Sea coast.

scholarly journals Yes, they can: polar bears Ursus maritimus successfully hunt Svalbard reindeer Rangifer tarandus platyrhynchus

Polar Biology ◽  
2021 ◽  
Author(s):  
Lech Stempniewicz ◽  
Izabela Kulaszewicz ◽  
Jon Aars
Keyword(s):  
Polar Bear ◽  
Rangifer Tarandus ◽  
Terrestrial Ecosystem ◽  
Ice Cover ◽  
High Energy ◽  
Ursus Maritimus ◽  
The Arctic ◽  
Attractive Potential ◽  
Polar Bears ◽  
Svalbard Reindeer

AbstractThe polar bear Ursus maritimus is one of the species most endangered by the rapidly declining sea–ice cover in the Arctic, which they use as a platform to hunt fatty, high-energy seals. In recent decades, more polar bears have been forced to remain longer on land, so their access to seals is limited. The importance of terrestrial food to polar bears is disputable, and more data are needed. Terrestrial ungulates could be an attractive substitute prey for them. Svalbard reindeer Rangifer tarandus platyrhynchus are prevalent and their distribution is completely within the range of polar bears. They constitute an attractive potential prey offering a significant energy return. Pre-2000 sources state that polar bears do not attack Svalbard reindeer. This report is the first description and documentation of the complete course of a polar bear hunt for adult reindeer in Hornsund, SW Spitsbergen, and also of the bear’s hunting behaviour and the reindeer’s response. Further, we report several other recent instances of bear–reindeer interactions in Svalbard, suggesting that polar bears now hunt reindeer more frequently than they used to. This increase in hunting is probably linked to the reduced ice cover, with bears spending more time on land, and a growing reindeer population. This study adds to earlier papers on how polar bears in Svalbard have increasingly shifted to a more terrestrial diet, and indicates that they may have an enhanced role as an apex predator in the terrestrial ecosystem.

scholarly journals Use of Subsistence-Harvested Whale Carcasses by Polar Bears in the Southern Beaufort Sea

ARCTIC ◽  
2019 ◽  
Vol 72 (4) ◽  
pp. 404-412 ◽  
Author(s):  
Kate M. Lillie ◽  
Eric M. Gese ◽  
Todd C. Atwood ◽  
Mary M. Conner
Keyword(s):  
Polar Bear ◽  
Indigenous Communities ◽  
Beaufort Sea ◽  
Bowhead Whale ◽  
Annual Number ◽  
Polar Bears ◽  
Northern Coast ◽  
Open Population ◽  
Hair Samples ◽  
Northern Alaska

The availability of a food subsidy has the potential to influence the condition, behavior, fitness, and population dynamics of a species. Since the early 2000s, monitoring efforts along the coast of northern Alaska have indicated a higher proportion of polar bears (<i>Ursus maritimus</i>) of the southern Beaufort Sea (SB) subpopulation coming onshore to feed on subsistence-harvested bowhead whale (<i>Balaena mysticetus</i>) carcasses during the fall and early winter seasons. Concurrently, Indigenous communities annually hunt bowhead whale and deposit the unused remains at localized “bone piles,” creating the potential for human-bear interactions. Our objective was to determine the annual number of polar bears feeding at the bone pile near Kaktovik, Alaska. Using a hair snag surrounding the bone pile, we collected hair samples to identify individual bears via microsatellite genotypes during 2011 – 14. We used capture-mark-recapture data in the POPAN open-population model to estimate the number of bears visiting the bone pile. We estimated that as many as 72 (SE = 9) and 76 (SE = 10) male and female polar bears, respectively, used the bone pile located at Kaktovik, Alaska, in 2012, which represents approximately 16% of the SB polar bear subpopulation. It will be important to monitor the number of bears using the bone pile and subsequent human-bear interactions and conflicts along the northern coast of Alaska, if sea ice continues to recede.

scholarly journals Iñupiaq Knowledge of Polar Bears (Ursus maritimus) in the Southern Beaufort Sea, Alaska

ARCTIC ◽  
2021 ◽  
Vol 74 (3) ◽  
pp. 239-257
Author(s):  
Karyn D. Rode ◽  
Hannah Voorhees ◽  
Henry P. Huntington ◽  
George M. Durner
Keyword(s):  
Sea Ice ◽  
Polar Bear ◽  
Late Summer ◽  
Beaufort Sea ◽  
Ursus Maritimus ◽  
The Arctic ◽  
Polar Bears ◽  
Structured Interviews ◽  
Ice Breakup ◽  
Pack Ice

Successful wildlife management depends upon coordination and consultation with local communities. However, much of the research used to inform management is often derived solely from data collected directly from wildlife. Indigenous people living in the Arctic have a close connection to their environment, which provides unique opportunities to observe their environment and the ecology of Arctic species. Further, most northern Arctic communities occur within the range of polar bears (nanuq, Ursus maritimus) and have experienced significant climatic changes. Here, we used semi-structured interviews from 2017 to 2019 to document Iñupiaq knowledge of polar bears observed over four decades in four Alaskan communities in the range of the Southern Beaufort Sea polar bear subpopulation: Wainwright, Utqiaġvik, Nuiqsut, and Kaktovik. All but one of 47 participants described directional and notable changes in sea ice, including earlier ice breakup, later ice return, thinner ice, and less multiyear pack ice. These changes corresponded with observations of bears spending more time on land during the late summer and early fall in recent decades—observations consistent with scientific and Indigenous knowledge studies in Alaska, Canada, and Greenland. Participants noted that polar bear and seal body condition and local abundance either varied geographically or exhibited no patterns. However, participants described a recent phenomenon of bears being exhausted and lethargic when arriving on shore in the summer and fall after extensive swims from the pack ice. Further, several participants suggested that maternal denning is occurring more often on land than sea ice. Participants indicated that village and regional governments are increasingly challenged to obtain resources needed to keep their communities safe as polar bears spend more time on land, an issue that is likely to be exacerbated both in this region and elsewhere as sea ice loss continues. 

Climate-associated drivers of plasma cytokines and contaminant concentrations in Beaufort Sea polar bears (Ursus maritimus)

2020 ◽  
Vol 745 ◽  
pp. 140978
Author(s):  
Jennifer Bourque ◽  
Jean-Pierre Desforges ◽  
Milton Levin ◽  
Todd C. Atwood ◽  
Christian Sonne ◽  
...  
Keyword(s):  
Beaufort Sea ◽  
Ursus Maritimus ◽  
Polar Bears ◽  
Plasma Cytokines

Summer refugia of polar bears (Ursus maritimus) in the southern Beaufort Sea

Polar Biology ◽  
2016 ◽  
Vol 40 (4) ◽  
pp. 753-763 ◽  
Author(s):  
Jodie D. Pongracz ◽  
Andrew E. Derocher
Keyword(s):  
Beaufort Sea ◽  
Ursus Maritimus ◽  
Polar Bears

Research and management of polar bears Ursus maritimus

Polar Record ◽  
1986 ◽  
Vol 23 (143) ◽  
pp. 167-176 ◽  
Author(s):  
Ian Stirling
Keyword(s):  
Natural Resources ◽  
Polar Bear ◽  
World Wide ◽  
Ursus Maritimus ◽  
Polar Bears ◽  
International Agreement ◽  
International Union ◽  
International Coordination ◽  
The 1950S ◽  
Circumpolar Arctic

AbstractThrough the 1950s and 1960s there was a marked increase in recorded numbers of polar bears being killed for their hides, giving rise to world-wide concern that the species might be endangered. At a meeting in Fairbanks, Alaska 1965, representatives of circumpolar arctic nations discussed conservation of polar bears and concluded that international coordination of research and management efforts was essential. Subsequent meetings of scientists engaged in polar bear research were organized every two years by the International Union for the Conservation of Nature and Natural Resources, facilitating exchanges of views and cooperation; as a result, in 1973 the International Agreement on the Conservation of Polar Bears and their Habitats was signed in Oslo, Norway. This paper describes some of the research and management undertaken in the years leading up to the agreement, and initiatives that are continuing because of it.

Unusual Predation Attempts of Polar Bears on Ringed Seals in the Southern Beaufort Sea: Possible Significance of Changing Spring Ice Conditions

ARCTIC ◽  
2009 ◽  
Vol 61 (1) ◽  
pp. 14 ◽  
Author(s):  
Ian Stirling ◽  
Evan Richardson ◽  
Gregory W. Thiemann ◽  
Andrew E. Derocher
Keyword(s):  
Sea Ice ◽  
Polar Bear ◽  
Foraging Behaviour ◽  
Open Water ◽  
Beaufort Sea ◽  
Polar Bears ◽  
Ringed Seals ◽  
Decadal Scale ◽  
Underlying Causes ◽  
Ice Conditions

In April and May 2003 through 2006, unusually rough and rafted sea ice extended for several tens of kilometres offshore in the southeastern Beaufort Sea from about Atkinson Point to the Alaska border. Hunting success of polar bears (Ursus maritimus) seeking seals was low despite extensive searching for prey. It is unknown whether seals were less abundant in comparison to other years or less accessible because they maintained breathing holes below rafted ice rather than snowdrifts, or whether some other factor was involved. However, we found 13 sites where polar bears had clawed holes through rafted ice in attempts to capture ringed seals (Phoca hispida) in 2005 through 2006 and another site during an additional research project in 2007. Ice thickness at the 12 sites that we measured averaged 41 cm. These observations, along with cannibalized and starved polar bears found on the sea ice in the same general area in the springs of 2004 through 2006, suggest that during those years, polar bears in the southern Beaufort Sea were nutritionally stressed. Searches made farther north during the same period and using the same methods produced no similar observations near Banks Island or in Amundsen Gulf. A possible underlying ecological explanation is a decadal-scale downturn in seal populations. But a more likely explanation is major changes in the sea-ice and marine environment resulting from record amounts and duration of open water in the Beaufort and Chukchi seas, possibly influenced by climate warming. Because the underlying causes of observed changes in polar bear body condition and foraging behaviour are unknown, further study is warranted.

Trichinella and polar bears: a limited risk for humans

2017 ◽  
Vol 91 (4) ◽  
pp. 440-446 ◽  
Author(s):  
J. Dupouy-Camet ◽  
P. Bourée ◽  
H. Yera
Keyword(s):  
World War Ii ◽  
Polar Bear ◽  
Ursus Maritimus ◽  
The Arctic ◽  
Polar Bears ◽  
World War ◽  
Protected Species ◽  
Brown Bears ◽  
Limited Access ◽  
Human Trichinellosis

AbstractIn this review, we identified 63 cases reported since World War II of human trichinellosis linked to the consumption of parasitized polar bear (Ursus maritimus) meat. This low number contrasts to the numerous cases of human trichinellosis related to consumption of the meat of black (U. americanus) or brown bears (U. arctos). The prevalence of Trichinella infection is high in bears, but larval muscular burden is usually lower in polar bears compared to other bear species. Polar bears, therefore, seem to play a limited role in the transmission of trichinellosis to humans, as native residents living in the Arctic traditionally consume well-cooked bear meat, and travellers and foreign hunters have only limited access to this protected species due to the declining polar bear population.

An observation of possible cannibalism by polar bears (Ursus maritimus)

1985 ◽  
Vol 63 (6) ◽  
pp. 1516-1517 ◽  
Author(s):  
N. J. Lunn ◽  
G. B. Stenhouse
Keyword(s):  
Adult Female ◽  
Adult Male ◽  
Physical Condition ◽  
Polar Bear ◽  
Ursus Maritimus ◽  
Polar Bears ◽  
Ecological Significance ◽  
Natural Conditions ◽  
Old Adult

We observed a case of cannibalism by a 23-year-old adult male polar bear in very poor physical condition on Southampton Island, N.W.T. It had apparently killed an adult female and was feeding on the carcass. Cannibalism among polar bears does occur under natural conditions. It is difficult to document how often this occurs and of what ecological significance it might be.

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